Ferric acid, salts

Chimique (43 vols., 1882-7 the set seen). Besides research on organic chemistry, Fremy characterised ferric acid, salts of which had been noticed by Stahl (see Vol. II, p. 682) and Ekeberg and investigated by J. Denham Smith. Fremy also investigated the stannic acids, and antimonic acids and antimonates. ... 

Ferri- and ferrocyanides - 401, 408 Ferric acetate - 171, 193, 266 Ferric acid salts - 60, 149, 392 Ferric ammonium sulfate - 19, 231, 660 Ferric-chlorate ion - 384... 

A reaction in which an electrophile participates in het-erolytic substitution of another molecular entity that supplies both of the bonding electrons. In the case of aromatic electrophilic substitution (AES), one electrophile (typically a proton) is substituted by another electron-deficient species. AES reactions include halogenation (which is often catalyzed by the presence of a Lewis acid salt such as ferric chloride or aluminum chloride), nitration, and so-called Friedel-Crafts acylation and alkylation reactions. On the basis of the extensive literature on AES reactions, one can readily rationalize how this process leads to the synthesis of many substituted aromatic compounds. This is accomplished by considering how the transition states structurally resemble the carbonium ion intermediates in an AES reaction. 

A study of the viseosit - of solutions of ferric oxide in aqueous arsenic acid at concentrations between 2-6 and 23-3 per cent. As2Os shows2 that two solid phases exist within these limits, the normal salt, FeAs04.rrH,0 (so about 3), which adsorbs arsenic acid, and an acid salt of composition Fe203.2Asa05.8H20, which has also been obtained by the action of excess of arsenic acid on a solution of ferric chloride. 

Several ferric selenites have been described, and may be divided into three groups, namely basic, neutral, and acid salts.5... 

A hydrated acid salt, 2Fe2(HAs04)3.9H20, results when solutions of disodium hydrogen arsenate and ferric chloride are mixed. The salt separates out as a white precipitate, soluble m aqueous hydrogen chloride. 

The discussion above has assumed a Fe /OH stoichiometry of 1/3 for the oxyhydroxides. There is convincing evidence, however, that the freshly precipitated oxyhydroxides formed in acid salt solutions, especially above 0.05M, are initially deficient in OH (38,39). According to Murphy et al. (40), the initial precipitate upon neutralization is comprised of spherical polycations, 15 to 35 A in diameter. These are presumably the small ferric-hydroxy polymers described by Dousma and deBruyn ( ) which form reversibly and rapidly from precursor monomers and dimers. The next step is the formation of large polymers (, 39). The hydroxide deficiency (+ charge) of the small and large polymers is compensated for by adsorbed and/or coprecipitated anions such as Cl, N03, and CIO. Several studies have shown that such anion-enriched polymers can persist at ambient temperatures, particularly at high anion concentrations in acid solution. Thus, Biedermann and Chow (42) report a two-month old precipitate with the composition Fe(OH)2 yClg 3 formed from 0.5 M NaCl solutions, and Fox... 

Ethyienediaminetetracetic acid, ferric ammonium salt Ferrate(-I), ((N,N -1,2-ethanediylbis(N-(oarboxymethyl)-glycinato))(4-)-N,N, 0,0, 0N,0N )-, ammonium Ferrate-(l-),... 

The LB technique may also be combined with solid-state chemistry methods to produce novel molecular architectures. For example, a network of conductive polypyrrole (molecular wires ) may be obtained in a fatty acid matrix [37, 38]. First, monolayers of the iron salt of a long-chain fatty acid (e.g., ferric pahnitate) are assembled on an appropriate substrate. The multilayer film is then exposed to saturated HCl vapor at room temperature for several minutes. During this process, a chemical reaction transforms the fatty acid salt into layers of ferric chloride separated by layers of fatty acid. In the third and final step, the film is exposed to pyrrole vapor and a reaction occurs between the pyrrole and the ferric chloride, producing polypyrrole distributed within the multilayer assembly. 

Ethylenediaminetetraacetic acid, ferric-sodium salt Ethylenediaminetetraacetic acid, sodium ferric salt. See Sodium ferric EDTA Ethylenediaminetetraacetic acid, sodium salt Ethylenediaminetetraacetic acid, tetrasodium salt. See Tetrasodium EDTA Ethylenediaminetetraacetic acid, tripotassium salt. See Tripotassium EDTA Ethylenediaminetetraacetic acid, trisodium salt. See Trisodium EDTA... 

Arsenic found in lewisite is converted in the red and charcoal-L processes into chlorovinylarsonic acid (CVA) in quantities of up to 3 percent by weight in the neutralent waste stream (Table 2-2). The fate of CVA depends on the posttreatment processes. In a SCWO reactor and in the GPCR caustic scrubber brine, the CVA is expected to be converted to sodium arsenate salts (e.g., Na3As04 and Na4As207), which can then be treated with ferric chloride to produce ferric arsenic salts for disposal in a hazardous waste landfill. This treatment scheme, which was developed in Canada, is... 

The hypothetical polarization curve shown in Figure 5.2 illustrates a near-realistic industrial condition since most corroding solutions contain more than one oxidizing agent. Normally, ferric-ferrous salts and other ionic impurities are contained in acid solutions due to contamination from corrosion products and existing oxidizers [4]. Nevertheless, the electrochemical situation shown in Figure 5.2 implies that... 

Resistance to neutral, alkaline, and acid salts is shown, but poor resistance is foimd with oxidizing acid salts such as ferric chloride. 

Colorations or coloured precipitates are frequently given by the reaction of ferric chloride solution with.(i) solutions of neutral salts of acids, (ii) phenols and many of their derivatives, (iii) a few amines. If a free acid is under investigation it must first be neutralised as follows Place about 01 g. of the acid in a boiling-tube and add a slight excess of ammonia solution, i,e., until the solution is just alkaline to litmus-paper. Add a piece of unglazed porcelain and boil until the odour of ammonia is completely removed, and then cool. To the solution so obtained add a few drops of the "neutralised ferric chloride solution. Perform this test with the following acids and note the result ... 

Unless all the excess of ammonia has been driven off in the preparation of the neutral salt, the result obtained on adding ferric chloride will be misleading owing to the precipitation of ferric hydroxide. If this is suspected, the tests should be repeated using an aqueous solution of the pure sodium salts of these acids for comparison. 

As esters are usually difficult to detect, this test is of considerable value. In general esters react when heated with hydroxylamine to give a hydroxamic acid (I). The latter gives a coloured complex (II) with ferric salts in acid solution. 

The neutral salts of many acids treated with ferric chloride give colorations or precipitates. 

Succinate, benzoate, phthalate and cinnamate give buff or brownish coloured precipitates of the basic ferric salts in the cold. Add dil. H2SO4. The basic ferric succinate dissolves giving a clear solution the other basic ferric salts also dissolve, but simultaneously a white precipitate of the free acid is also formed. 

Fenton s reagent. To a solution of tartaric acid or a tartrate add 1 drop of freshly prepared ferrous sulphate solution, i drop of hydrogen peroxide solution and then excess of NaOH solution an intense violet coloration is produced, due to the ferric salt of dihydroxyfumaric acid, HOOC C(OH) C(OH)COOH. 

Aqueous solutions give with ferric chloride the characteristic reactions of the neutral salt of the acid (p. 348). Identify the carboxylic acids by the tests already given (Section 14, p. 347), or by the preparation of one of the crystalline derivatives below. 

Upon boiling the alkaline ferrous salt solution, some ferric ions are inevitably produced by the action of the air upon the addition of dilute siilphurio acid, thus dissolving the ferrous and ferric hydroxides, the ferrocyanides reacts with the ferric salt producing ferric ferrocyanide (Prussian blue) ... 

Esters react witli hydroxylamine to form an alcohol and a hydroxamic acid, RCONHOH. All hydroxamic acids, in acid solutions, react with ferric chloride to form coloured (usually violet) complex salts ... 

In 1877, Nencki (22) condensing ammonium thiocyanate with chloroacetic acid, attributed the name rhodaninic acid (Rhodaninsaure) to the compound he obtained. He noted the ability of rhodaninic acid to give colored derivatives with ferric salts. 

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